Hamiltonian Four-Field Model for Nonlinear Tokamak Dynamics

摘要

The Hamiltonian four-field model is a simplified description of nonlinear tokamak dynamics that allows for finite ion Larmor radius physics as well as other effects related to compressibility and electron adiabaticity. Much simpler than a rigorous or even reduced description of the same physics, it still preserves essential features of the underlying exact dynamics. In particular, because it is a Hamiltonian dynamical system it conserves the appropriate Casimir invariants, as well as avoiding implicit, unphysical dissipation. Here the model is derived and interpreted, its Hamiltonian nature is demonstrated, and its constants of motion are extracted. (ERA citation 12:026277)